1. Field of the Invention
This invention relates to a method of casting iron, steel aluminum or the like and an apparatus therefor, and more specifically to such a method and apparatus for pouring molten metal from a ladle of special configuration and construction into a mold. The present invention is effectively applicable to a equipment for continuous casting iron, steel, aluminum or the like.
2. Description of the Prior Art
In the casting industry it is customary that the pouring of molten metal into molds depends on the knack of skilled operators long experienced in the art. Molten metal is carried in a ladle, usually of a generally cylindrical contour provided with an outlet on a top part, to a pouring section where a series of molds are arranged. Since the ladle usually is held by suspending means, the operator must rotate the ladle into the position where it pours molten metal into the pouring cup of the mold. At that point, the ladle outlet and the pouring cup of the mold are a certain distance apart, the distance being varied with further rotation of the ladle. In addition, the tilting of the ladle changes the surface area of molten metal in the vessel. If the ladle is tilted at a constant velocity, the volume of molten metal being poured will undergo gradual changes. The operator is, therefore, required to adjust both the position of the ladle outlet with respect to the pouring cup of the mold and the angle of ladle inclination while observing the curve of molten metal flow so as to compensate for the variations in the distance between the ladle outlet and the pouring cup of the mold and also in the amount of molten metal being poured. As noted above, these operations are very difficult and demand a high degree of technical skill. Moreover, the operations are extremely dangerous.
A common practice with the modern equipment for continuous casting of iron, steel, aluminum, etc. is to have molds as cope-drag combinations made, in succession, on a molding line, deliver the molds on a continuous mold conveyor line of the tact drive type, thereby moving the molds successively to a pouring section, tap a melting furance and fill the ladle with molten metal, and then a skilled operator tilts the ladle toward the pouring cup of each empty mold and pour the melt under control so that a suitable quantity of molten metal is supplied to the mold.
The foundry environment for these operations is very hazardous and poor with high temperature required and frequent splashing of the molten metal, such as iron or aluminum, against the surroundings. Further, as noted above, the pouring operation needs a high degree of skill and therefore well experienced workers.
For these reasons, there has long been a great need for an unattended, automatic pouring system. Attempts thus far made to meet this need include automatic pouring apparatuses of an electromagnetic induction conveyor type and of a valve type for hot pig iron. Both are of the so-called fixed-point type which operate stationarily while maintaining a large volume of metal in a melted state. Each mold is conveyed to a position exactly aligned to the outlet of the pouring apparatus and then the molten metal is poured into the mold. Therefore, a casting equipment must be installed to suit such an automatic pouring apparatus. While those automatic apparatuses are adapted for use with the new high-speed continuous casting installations of most modern designs, they cannot be readily incorporated into the existing casting plants. Also, the prior art automatic apparatuses are not suited for use with the casting equipment which does not employ the continuous mold conveyor system, or for pouring molten metal into molds arranged over a flat plane on a floor level, for example for forming large castings. Among other drawbacks of the conventional automatic apparatuses are very high cost of the electromagnetic induction conveyor type and frequent troubles with valves of the valve type for hot pig iron. Both require great skill and much expenses for the maintenance and inspection after routine operation. Once a trouble arises, they will need a long downtime. Nevertheless, because of the costliness of the apparatuses, it is practically impossible for founders to retain any stand-by unit.